I'm going to have a little crack at this, although I'm sure there are folks here who know way more than me.

Which Transmitter are you using? Does it have an option to switch between "mode 1" and "mode 2". The difference between these is the throttle and elevator controls switch places on the transmitter, which some people prefer. Could you have accidentally changed it?

If you want the controls on the right stick, which it what I use at the moment, I have mine plugged into Aile and Elev, mode 2, with delta mixing on. (I have a Spektrum DX5)

Hopefully I've not misunderstood and been a complete tool.